Internal-combustion engine



June 14, 1938.

J. BARRAJA-FRAUENFELDER INTERNAL COMBUST ION ENGINE Filed Feb. 3. 1937 il i f .Q Mo

Patented June i4; 1,938

'Joseph Baraja-Frauenfelder. lSwan-tl:more,,lily.. y' I assigner-to Sun Shipbuilding a Dry Dockiltnni' :y pm, Chester, Pa.. a corporation or Pennlyl- 1 v a 4 t Application rdimm/rs, 1931, serial No. 123.930' Y a calma (ci, y12a-51) y This invention relates to an improvement'in internal combustion engines and more particularly to an improvement in opposed piston engines of the fuel injection or Diesel type.

Heretofore in opposed piston engines of the fuel injection or Diesel type disadvantage has been noted from the fact that lubricating oil working up the side rods which connect the outer piston with the crank shaft is thrown off against the outer working piston at the beginning' of its outer stroke and by the piston carried into the working cylinder wherein it is lst.

Again, disadvantage is found in opposed piston engines of the type indicated wherein a scavenging air pump is provided for operation by connection of the scavenging air pump piston with the outer working piston, since lubricating oil working up the side rods, which are encompassed by the scavengingy air pump cylinder, is thrown from the rods to the wall of the scavenging air pump cylinder from where it works through into the suction side and is consumed with the scavenging air.

Various efforts have been made to avoid the loss of lubricating oil which, escaping from the crank pins, tends to work up the side rods. Thus, for example, the side rods have been equipped with deectors with the idea o! stopping the travel of the oil up the rods andy causing it to return to the crank case. However, such means have proved unsatisfactory, lsince lit has been found that the oil will work around the deflectors and continue up the rods to be thrown oil from the upper ends of the rods against the working piston and the scavenging air pump cylinder with resultant loss. l

Now, in accordance with4 this invention means are provided whereby oil working. up the side rods and being thrown oi from the upper end thereof will be prevented from reaching the working piston and Ahence from being carried into the working cylinder and whereby the passage of oil which may be thrown against the wall of the scavenging air pump cylinder will be prevented from working up past the scavenging air pump plston and hence from entry into the working cylinder with the scavenging air.

More` particularly, in accordance with this invention the outer end of-*the working piston is provided with a skirt or deflector arranged to receive oil thereon from the vends of the side rods and prevent Vits reaching the surface of theworking piston, while," at the same time; ythe scavenging air piston is provided with a trunk working on the wall of the scavenging air-cylinder,

of such length with respect to the stroke of piston that oil thrown from the rods against the wall of the scavening' air cylinder will not .work

by the piston. f

Having indicated in a general way the nature" and purpose of this invention, Il will now proceed to a detailed description thereof with reierence to the accompanying drawing in which al preferred embodimentis illustrated and in which the single figure is a sectional view oi.' an opposed piston engine of the fuel injection or Diesel type in accordance with this invention.

In the single figure, i indicates the frame of the engine in which is supported the usual crank shaft. 4 indicates a` working cylinder in which the usual opposedgpistons operate and of which the outer plstonjgcontrolling the scavenging air ports 9, which are in communicationwith the usual scavenging "air receiver it, is shown. The inner end of the working cylinder is provided with the usual exhaust ports controlled by the inner oi' the two opposed working pistons.

AThe outer working piston 6 is connected with the crankshaft by means of side rods il, i2, through the medium of pin or cross head Il'.

Mounted on lthe frame I is a scavenging air pump cylinder, of a diameter such as to accommodate the side'rodsflz, i2 and pin or-.cross head il, provided with a headli connected with scavenging air receiver lilfthrough puppet valves work'inthe scav'lising airpump cylinder i4, vis

directly connectdfto ytlieotei end of the'outer piston 6;

At theout'er end of the outer piston 8, beneath the bearingslll,` for the suplvaort 'oi vthe pin or vcross head i3', is a depehdingfannular ilange or skirt. 2i, `oi.' a diametertin'excess of the outer diameter of the working'cylinder and of a depth such as to extend substantially below the upper `ends of the siderodssii, l2 at their point of conves il, il. Thev eral,` of an ired'fc ystruction,and is directly v i chamber iii lopen', to lthe atmosphere through an n aperture i1 .through 'pup connected with the outer workingA piston 6 in any desired manner.- The scavenging air pump piston is, however, particularly characterized by the fact that its trunk I9', provided with a single compression ring 22, is of a height to provide a long bearing surface with the wall of the scavenglng air pump cylinder I4 and is of a height from V; of the length of its stroke to in excess of the length of its stroke. When the piston is in its lower dead center position, the lower portion of the trunk extends beyond the wall of the scavenging air pump cylinder, as shownin dotted lines in the drawing.

The operation of the engine embodying this invention will, it is believed, be readily understood. In general, the engine operates through the usual cycle and in the usual manner for engines of the fuel injection or Diesel type. That is to say, on the inner or compression stroke of the working pistons air is compressed between them, fuel is injected into the cylinder between the pistons through a fuel injection device entered in the threaded aperture 23 at the proper time, the pistons are forced apart by expansion of the fuel on combustion, the burned gases are exhausted through the exhaust ports 1, which are Opened by the inner piston 5, and the working cylinder is scavenged by scavenging air entering through the scavenging air ports 9, which are opened by the outer piston 6 after opening of the exhaust ports.

The work upon the outer working piston 6 is transmitted to the crank shaft through the pin or cross head Il through the side rods I3, il, while the work upon the inner piston is transmitted to the crank shaft through the connecting rod II.

The necessary scavenging air is provided by the operation of the scavenging air piston I8 in the scavenging air cylinder Il, supply of fresh air being drawn by the piston through puppet valves I8, I8 and the air compressed by the piston being discharged through puppet valves I8, I8 into the scavenging air receiver I0, from which it passes to the working cylinder through the scavenging ports 9.

In the operation of the engine, assuming, for example, as is usual, that the crank pins are lubricated by forced speed of oil through passage formed in the crank shaft, a certain amount of oil will escape from the ends of the crank pin bearings and a, portion thereof will be picked up by the side rods I3, I3. Oil picked up by the side rods will work itself along the surface of the rods until it reaches the ends thereof adjacent their connection with the pin or cross head I3, at which point the oil will be thrown oil! the rods.

Oil, as indicated at z, thrown 01T from the ends of the rods will in part impinge against or be caught by the depending, annular flange or skirt 2| at the outer end of the outer working piston and will, in the reciprocation of the piston, drip therefrom clear of the surface of the piston and of the working cylinder, since the diameter of the flange is such that it is considerably in excess of the outer diameter of the piston and in excess of the outer diameter of the working cylinder. Since the depending ange or skirt 2i extends below the outer end of the working cylinder in the lower dead center position of the outer working piston, oil caught by the outer face of the flange will be positively prevented from entering the working cylinder in the change in the direction of motion of the outer piston from an inward direction to an outward direction with respect to the working cylinder when force will be exerted upon oil carried on the outer face of the flange or skirt 2 I tending to throw it oil' the face or the flange of skirt as shown at x'.

Again, oil, as shown at y, thrown of! from the ends of the rods Il, I3, will be thrown upon the surface of the scavenging air pump cylinder Il.

I Due to the height of the trunk of the scavenging air pump piston, such oil will not be able to work by the piston in the downward stroke thereof and will be carried below the wall of the scavenging air pump cylinder when the piston reaches its lower dead center position. As a result, not only will oil thrown against the scavenging air pump cylinder be prevented from passing the piston due to the length of its trunk, but such oil will be discharged from the inner end of the scavenging air pump cylinder due to the extension of the trunk of the scavenging air pump cylinder when the piston is in lower dead center position, as shown at il'.

The operation of the engine embodying this invention, with respect to the avoidance of loss of oil working by the side rods through entry thereof into the working cylinder, directly or through the scavenging air pump, will, it is believed. be entirely clear from the above description in conn ection with the drawing and, in particular, with reference to the showing in dotted lines of the outer Working piston and the scavenging air piston.

It will be understood that the embodiment of this invention, as above described in detail, is so described for the purpose of illustration only and it is to be understood that various modifications in detail as involved in the above description may be made Without departing from the scope of this invention, which is contemplated as capable of various embodiments other than that as above described.

What I claim and desire to protect by Letters Patent is:

1. In an internal combustion engine of the opposed piston type, in combination, a working cylinder, an outer working piston in said cylinder, side rods connected to the outer working piston and an annular flange on said outer piston extending inwardly from adjacent the points of connection of said piston with said side rods, said annular flange being of a diameter greater than the outside diameter of the end of the working cylinder and the flange being of such length as to embrace the end of the working cylinder when the outer working piston is in inner dead center position.

2. In an internal combustion engine of the opposed piston type, in combination, a working cylinder, an outer working piston in said cylinder, side rods connected to the outer working piston, a scavenging air pump cylinder mounted adjacent the outer end of the working cylinder and of a, diameter to embrace said side rods, a scavenging air pump piston within the scavenging air pump cylinder, the trunk of said piston working on the wall of the scavenging air pump cylinder being of a height of from one-third of the length of its stroke to in excess of the full length of its stroke and an annular flange on said outer piston extending inwardly from adjacent the points of connection of said piston with said side rods, said annular flange being of a diameter greater than the outside diameter of the end of the Working cylinder and the flange being of such length as to embrace the end of the working cylinder when the outer working piston is in dead center position.

3. In an internal combustion engine of the opposed piston type, in combination, a working cylinder, an outer working piston in said cylinder, side rods connected to the outer working piston, a scavenging air pump cylinder mounted adjacent the outer end of the working cylinder and of a diameter to embrace said side rods, a scavenging air pump piston within the scavenging* air pump cylinder, the trunk of said scavenging air pump piston working on the wall of the scavenging air pump cylinder being of a height of from one-third of the length of its stroke to in excess of the full length of its stroke and arranged to extend beyond the end of the wall of the scavenging air pump cylinder when the piston is in lower dead center ition whereby oil thrown on the wall of ,the sgglenging air pump cylinder is prevented from b'y-passing the scavenging air pump piston.

JOSEPH BARRAJA-FRAUENFELDER. 

